Obesity occurs in nearly 27% of American women. Its increase in prevalence with age and menopause is associated with an increased risk of diabetes, hyperlipidemia, hypertension, cardiovascular disease (CVD) and other illnesses that cost the nation more than $40 billion annually. Obesity is both a behavioral and a metabolic disease, hence weight loss (WL) interventions must impact on both psychobehavioral and biological processes. This obesity research is based on the premise that the self efficacy beliefs and adipose tissue metabolism of postmenopausal women are linked to WL and its maintenance. The hypotheses are that: l) multi- faceted interventions that target distinct self efficacy needs will more effectively modify cognitions, emotions, and behavior to diminish food intake, increase total daily energy expenditure, and promote WL and adaptations in lipid, glucose, adipose tissue metabolism than usual care; and 2) psychobehavioral as well as metabolic adaptations to WL and its self efficacy directed WL and relapse prevention treatments will be necessary to maintain the weight-reduced state. Ninety obese (BMI 27-40 kg/m2), healthy, non-smoking, 50-60 year old postmenopausal women not on medications (esp. estrogen) known to affect obesity, metabolism or behavior will be studied. To determine the effects of self efficacy targeted interventions, women will be stratified by race and self efficacy type (Assureds and Disbelievers) and randomized to targeted treatments (psychobehavior, diet and low intensity exercise) or usual care. To determine whether WL and its maintenance requires both psychobehavioral and metabolic adaptations, women receive self efficacy directed WL and relapse prevention treatments (each lasting six months) or usual care of the same duration. The study design permits: l) cross-sectional analysis of psychobehavioral status, energy balance and metabolic function; 2) longitudinal determination of the behavioral and metabolic effects of self efficacy targeted WL and relapse prevention treatments; and 3) identification of psychobehavioral and metabolic adaptations required for WL and its maintenance. The emphasis of this clinical research on health promotion, disease prevention and individualized patient care makes nurses particularly well-suited to collaborate on interdisciplinary teams that deliver WL interventions focused on the personal beliefs and intrinsic needs of obese postmenopausal women.